An appraisal of the Suzuki cross-coupling reaction for the synthesis of novel fluorescent coumarin derivatives

Alhaj Zen, Amer; Aylott, Jonathan W.; Chan, Weng C.

Abstract

We report the chemical design and development of 3-aryl-substituted 7-alkoxy-4-methylcoumarins with enhanced fluorogenic properties. The 3-aryl substituents are installed via an optimized Suzuki–Miyaura cross-coupling (SMC) reaction between a 7-alkoxy-3-bromo-4-methylcoumarin and aryl boronic MIDA esters using Pd(OAc)2/XPhos in a catalytic system with K2CO3 in aqueous THF. Under these conditions, an exocyclic ester functionality is found to be unaffected. Subsequent saponification revealed a carboxylic acid functionality that is suitable for conjugation reactions. Evaluation of their fluorescence properties indicated that the installed 3-heteroaryl substituent, particularly benzofuran-2-yl, resulted in a significant red shift of both the excitation and emission wavelengths.

Citation

Alhaj Zen, A., Aylott, J. W., & Chan, W. C. (2014). An appraisal of the Suzuki cross-coupling reaction for the synthesis of novel fluorescent coumarin derivatives. Tetrahedron Letters, 55(40), https://doi.org/10.1016/j.tetlet.2014.08.058

• Journal Article Type: Article
• Acceptance Date: Aug 13, 2014
• Online Publication Date: Aug 19, 2014
• Publication Date: Oct 1, 2014
• Deposit Date: Oct 13, 2016
• Publicly Available Date: Oct 13, 2016
• Journal: Tetrahedron Letters
• Print ISSN: 0040-4039
• Electronic ISSN: 0040-4039
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 55
• Issue: 40
• DOI: https://doi.org/10.1016/j.tetlet.2014.08.058
• Keywords: Coumarin, Suzuki cross-coupling, Arylboronic MIDA ester, Fluorescence
• Public URL: https://nottingham-repository.worktribe.com/output/734550
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0040403914013926